Why do i'm itchy all over my body, my joints hurt, i'm always fatigued,?

Multiple causes: this could be thyroid disease, autoimmune dz, allergies, functional process....needs a medical evaluation .

Many possibilities: There are many conditions that could cause your symptoms: these can be very minor, or possibly more serious, so I would recommend seeing a doctor who can take a more detailed history: when, where, and what order the symptoms came on, etc and also probably order some lab tests depending on the history. The doctor will also want to know if there is/was a rash, swelling, what meds you are taking.